Briefly, QPR threatened an amazing victory, with Jamie Mackie putting them into a second-half lead.
It was the 14th time this season United have conceded the first goal, an astonishing statistic.
And after a brief panic, the Red Devils eventually turned the game round with three goals in nine minutes.
"We played for 10 or 15 minutes," said Ferguson.
"That was the sum total of our real performance from Manchester United.
"Of course it is frustrating we keep ending up in that position but when they scored it definitely sparked us up."